There is a need in industry, in the Department of Defense (DOD), and in homes, factories, and offices to perform remote analysis of nearby chemicals. For example, it may be desired to monitor the atmospheric gasses in and around an oil refinery to determine whether hydrogen sulfide is present, and to quantify its concentration if it is detected. The Department of Defense may desire to monitor a gas cloud heading toward an Army base to determine whether that cloud contains chemical warfare agents. Existing techniques, including TDLS (Tunable Diode Laser Spectroscopy), NDIR (Non-Dispersive InfraRed analysis), Polychromatry, and FTIR (Fourier Transform InfraRed analysis) all have limitations that, depending on the application, can limit their ability to detect atmospheric gasses at the desired level.
There is a need by the DoD and by industrial safety personnel to be able to identify unknown chemical contaminant in the atmosphere from afar. The problem can be very difficult because normal components of the atmosphere such as H2O and CO2 (water vapor and carbon dioxide) have spectral signatures that are similar to, and overlap with the spectral signature of many of the contaminants of interest.